Oral parafunctional habits and orofacial myofunctional dysfunctions are commonly observed in children and considered as contributory factors for temporomandibular disorders (TMD). The aim of this work was to describe the frequency of oral parafunctional habits and orofacial myofunctional dysfunctions and to evaluate the association between them and signs and symptoms of TMD in patients attending to the TMD section of the Pediatric Dentistry Department of the University of Buenos Aires. Data obtained from dental records performed during 2003-2007 were entered into a database registering age, gender, reason for consultation, psychological stress, signs, symptoms, diagnosis, dysfunctions and parafunctions, for statistical analysis. The sample was constituted by 133 patients (average age: 12 +/- 3 years old). Ninety six percent of patients showed dysfunctions and/or parafunctions. Regarding dysfunctions, they were present in 78% of the sample; 48% had dysfunctional swallowing; 45% oral and mixed breathing, and 29% chewing food on one preferred side. With regard to parafunctions, bruxism was present in 74% of cases, gum chewing habit in 55%, nail biting in 48%, biting in 28%, jaw play in 22%, and sucking in 14%. TMD symptoms were associated with total dysfunctions and parafunctions (p <0.05). Using multivariate analysis, results showed a significant correlation between masticatory dysfunction and clicking joint noise (p= 0.023) and bruxism as reason for consultation (p= 0.018). Dysfunctions and parafunctions showed in this study a high prevalence and were significantly associated with TMD symptoms.